New option to send the audio to the specified audio device. It can be useful to send the audio to a TV via a HDMI cable or a bluetooth device.

Some improvements on the playlist. Now it's possible to hide any column (right click to see the options). The search field is also hidden by default, a new search button shows/hides it. These changes are intended to prevent the playlist window to be too wide.

Due to bugs and problems with Qt 5, the packages for Ubuntu are now built again with Qt 4 by default.